BIOL 203 Exam 1 L2 Vocab Flashcards

Ion channels

forms pores that allows ions to cross the membrane

Transporters (carriers / pumps)

moves molecules across membranes

Receptors

receive extracellular signals

Cell adhesion molecules

helps cells stick to each other or the ECM

Structural/anchoring protein

such as connexins which form gap junction channels

Integral transmembrane proteins

one or more segments that fully span the bilipid layer

Peripheral proteins

proteins temporarily attached to or indirectly associated with the cell membrane via interactions with integral proteins

Cytoskeletal/structural proteins

like spectrin, found in red blood cells, where it forms a meshwork underneath the plasma membrane and helps maintain cell shape and flexibility

Glycocalyx

carbohydrate-rich layer that coats the external surface of the plasma membrane; contains glycoproteins, glycolipids, proteoglycans

Glycoproteins

proteins that have short carbohydrate chains (sugars) attached

Proteoglycans

proteins that have one or more very long carbohydrate chains called glycosaminoglycans (GaG’s) attached

Glycosaminoglycans (GaGs)

long, unbranched polysaccharides (sugar chains) made of repeating disaccharides — high negative charge > attract water > create gel-like layer

Simple diffusion

doesn’t involve proteins; molecules move directly through the phospholipid bilayer of the membrane (nonpolar, small, uncharged)

Facilitated diffusion

requires protein channels or carriers embedded in the membrane (polar, large, charged)

Ionotropic receptor

opens in direct response to the binding of a chemical ligand (ex: neurotransmitter)

Leak channel

active pore that that allows ions to diffuse across the membrane according to their electrochemical gradients

Active transport

requires energy (ATP) since it takes molecules from lower to higher concentration, against the gradient (ex: sodium-potassium pump)

Secondary active transport

substance moved against its concentration gradient without directly using ATP (uses energy that was originally created by primary to change the gradient)

Endocytosis

form of active, vesicular transport in which cell uses its plasma membrane to engulf extracellular materials, closing them in a membrane-bound vesicle that is brought into the cell

Phagocytosis

“cell eating” — engulfs large particles, like bacteria (only some immune cells)

Pinocytosis

“cell drinking” — engulfs extracellular fluid and dissolved solutes into small vesicles

Receptor-mediated endocytosis

uses receptors and clathrin-coated vesicles for selective uptake

Autocrine cell signaling

cell releases a signal that acts on itself (used for self-regulation)

Paracrine cell signaling

one cell releases a signal that acts on nearby cells

Endocrine cell signaling

cell releases hormones that travel in the bloodstream that target distant cells

Hormones

Released by endocrine glands, acts on distant targets

Cytokines

released by immune cells, regulates immune responses

Neurotransmitters

released by neurons at synapses; rapidly signals nearby neurons, muscles, glands

Growth factors

proteins that stimulate cell division, cell specialization (differentiation)

Centriole

role in organizing the microtubules which moves chromosomes during cell division

Kinesin (vesicle transport)

OUT, + end → away from nucleus; transports vesicles, organelles, proteins

Dynein (vesicle transport)

IN, - end → toward nucleus; important for recycling materials, positioning organelles